We will build a multichannel "bioprinter" for high-speed printing of DNA probe microspots. This technology provides an essential foundation for the coming BioChip revolution in diagnostic medicine. Virtually all of the high-density, biochip-style devices in development will demand fast, practical, and accurate methods of dispensing micronscale spots of biological reagents. MicroFab's ink-jet technology can extend biological fluid dispensing capabilities by 1000-fold in miniaturization and 100-fold in speed, making biochip production a practical reality. We will design our multichannel printer for the specific task of producing a diagnostic system for M. tuberculosis (Mtb). The long-range goal is to produce a robust, hand-held diagnostic kit that can give rapid ( l hr) identification of drug-resistant strains of the mycobacterium from clinical specimens. By the use of printed high-density DNA capture probe arrays, as many as 400 allelic variants can be probed for in one cm2. Thus, genomic screening for hundreds of Mtb variants can be envisioned within a massively-parallel, one-step kit format. In Phase I we will test multichannel printhead designs, using clinically- important Mtb DNA probes to assess the fidelity of final probe-target hybridization. Phase II should conclude with prototype arrays manufactured for experimental testing on clinical specimens. PROPOSED COMMERCIAL APPLICATION: M. tuberculosis is the number one killer among infectious diseases. Technology for producing fast diagnostic systems will be extremely valuable. More generally, a BioPrinter capable of producing immuno- and DNA-probe arrays at microscopic scale and high volume is needed throughout biomedicine and biotechnology .The system we will develop could easily become the preferred technology for all diagnostic array production world-wide.